70 THE LUNAR ECLIPSE [CH. IV A rule relating to the determination of the resultant valana cor- responding to the circle having half the sum of the diameters of the eclipsed and eclipsing bodies for its radius : 18. Take the sum of their arcs (i.e., of the aksa-valana and ayana-valana) when they are of like (directions) and the diffe- rence when they are of unlike directions. Multiply the Rsine of that (sum or difference) by the sum of the semi-diameters of the eclipsed and eclipsing bodies and divide by the radius: this result is the valana1 . The valana obtained by this rule is the Rsine of the valana corresponding the circle of radius equal to the sum of the semi-diameters of the eclipsed and eclipsing bodies. A rule relating to the determination of the corrected valana {sphuta- valana): 19-20. If the valana (obtained above) is of the same direc- tion (as the Moon's latitude) add it to the Moon's latitude; if it is of the contrary direction, subtract it (from the Moon's latitude). The (sum or difference thus obtained) is known as the corrected valana {sphufa-valana) in the case of solar and lunar eclipses 2 . In case that (corrected valana) is found to be greater than the sum of the semi-diameters of the eclipsed and eclipsing bodies, it should be subtracted from the entire sum of the semi-diameters of the eclipsed and eclipsing bodies and the remainder (thus ob- tained) should be taken as the (corrected) valana. The corrected valana is supposed to give the distance of the centre of the eclipsing body from the east-west line drawn through the centre of the ec- lipsed body in the projected figure. As pointed out by me in the Maha-Bhaskarlya, the addition or subtraction of the valana and the Moon's latitude is not proper. Both the quantities i Cf. MBh,v. 46-47 (i).
- Gf. MBh> v. 47.
